1. Field of the Invention
The present invention concerns a block body of growth substrate, like peat moss, packed in a casing for use when forcing cuttings, possibly from seeds, to young plants for transfer to plant pots or for directly planting out.
2. Description of Related Art
For the above-noted purpose, there is also known special vacuum formed plastic foil trays with cells of indentations; but, for environmental reasons, it should be preferred to use block bodies of the kind enveloped in a paper-like casing which decomposes to a greater or lesser degree as the time passes by. These block bodies may wholly be transferred to the plant pots at the planting out whereby the packing do not imply any remaining problems.
The casings used should be reasonably durable at the outset, partly in order to be handled mechanically in the production of the block bodies and partly in order to withstand the action of mounting the seeds or cuttings. Naturally the casing should be also be kept intact when the block bodies are to be transferred to the plant pots, which often happens after 3 to 6 weeks, for some plants, though only after about 1 year.
As a consequence of the block bodies having to be as small as possible for considerations of space, it occurs in the meantime that the roots reach the casing, which already may happen after about one week. It is acknowledged, that it will be better for the roots to grow a little out through the side of the block instead of being packed together at the inside of the casing, and in many market gardenings, it is preferred to treat the casings in order to produce holes or slits in them. However, this is both arduous and has little effect and it has been investigated whether it would be possible from the beginning to use a material with a more perceptible degree of perforation. Tests with respect to this have failed until now due to the fact that a suitable material then becomes so difficult to handle at the production of the block bodies, where it is a requirement that the mass production in question has to proceed without interruptions.
It has already been proposed that, with respect to this purpose, that a special "Agricultural Paper" be used, see e.g. published European Patent Application No. 0 255 690, consisting of two layers, namely of a layer of natural fiber material, i.e. pulp, and of a thin, porous layer of synthetic fibers, whereby there is aimed at the fiber material's rather quick decomposition after the planting out, and that the roots then may penetrate the outer cohesive layer.
However, it appears that the fiber material in connection with the small block sizes will take such a long time to decompose that the roots normally will pack together against such a layer. Besides that, such a material will also be relatively expensive, because it requires a special production at the relevant wet laying out. Furthermore, synthetic materials are no longer welcome in nature.